The present invention relates to sailing yachts and to a high performance keelless sailing yacht with fore and aft cambered foils for leeway control. The invention further relates to a keelless sailing yacht with dynamic ballast which is laterally movable to apply a variable counter-heeling force; a tiltable mast; cambered foils for cyclic and collective steering; and adjustable camber controls for adjusting lift and leeway. The foregoing features allow disclosed improvements and modifications to hull design.
In the keeled yacht, as is now known, leeway and heeling are controlled by a ballasted keel which extends fore and aft of the hull and below the same along the centerline or midplane. Steering is controlled by a rudder working with the keel to displace water laterally as the boat is moved which is then transmitted to the stern of the vessel as a sideways force. The keel is normally laterally fixed in position at the midplane but may be raisable or combined with a center board which may be raised. Even so, the fixed keel of the conventional sailing yacht is multifunctional, combining in a single appendage the functions of lateral resistance to leeway and righting moment from the ballast. As such, the righting moment and lateral resistance to leeway are design parameters that are established in the plans of the yacht and in its construction and are not adjustable thereafter. As a consequence, the angle of heel can only be further changed by adjustable internal ballast or by moving crew weight; but leeway is normally not adjustable once the yacht is built. The necessity of some leeway has always been presumed. All of the above factors are limitations and disadvantages of known yacht designs.